Gut 1996; 38: 801-802 801 Leading article

Diverticular disease and chronic idiopathic inflammatory bowel Gut: first published as 10.1136/gut.38.6.801 on 1 June 1996. Downloaded from disease: associations and masquerades

Diverticular disease of the sigmoid colon affects between tous cryptitis, a histiocytic and granulomatous reaction to 35 and 60% of the Western population over the age of disruptive crypt abscesses in the mucosa, a characteristic 60 years.1 2 Inflammatory bowel disease (IBD) is also feature of Crohn's disease,'7 18 may accompany the luminal common in the elderly Western population. Although this mucosal inflammatory response that occurs in diverticular patient group includes those with a long history of IBD, it disease. 14 is now well accepted that there is a second peak of inci- Patients with diverticulosis are generally in an older age dence of IBD in the elderly.-6 It is therefore not surprising group and may have coexistent atheromatous disease. that diverticular disease and IBD often coexist. However, The impact of relative ischaemia and changes in bacterial Crohn's disease and diverticulosis coexist more often than flora due to diverticulosis may cause the Crohn's-like would be expected by chance, particularly in elderly inflammatory response in the sigmoid colon (Gledhill A, women.7-10 Nevertheless the picture may not be as straight- Dixon MF. Crohn's-like reaction in diverticular disease forward as published reports suggest. Pathologically (data in preparation)). Similar Crohn's-like immunologi- diverticulosis and its local complications may closely mimic cal responses are well recognised in tissues adjacent to both ulcerative colitis and Crohn's disease. A review of colonic cancer.19 published reports suggests that the association between the The prognosis of patients purported to show coexist- conditions may be exaggerated. There is increasing recog- ence of Crohn's disease and diverticular disease in pub- nition of a particular form of IBD that affects the luminal lished reports seems remarkably good with many patients mucosa in the sigmoid colon with diverticular disease.'"-15 showing no evidence of recrudescence of Crohn's disease This disease may cause confusion with IBD but a small elsewhere.7 9 10 This suggests that some of these cases do number of such cases may represent a specific form ofIBD. simply represent complicated diverticulosis with patho- logical mimicry of Crohn's disease in the sigmoid resection specimen. The author strongly believes that, while there is Diverticulosis and Crohn's disease some evidence to suggest a link between sigmoid Crohn's In the older patient, Crohn's disease is more likely to disease and diverticulosis, substantiation of a diagnosis of http://gut.bmj.com/ affect the distal colon and anorectum than the proximal Crohn's disease should be sought by investigation of the colon and small bowel4 9 while the disease may also pre- remaining gastrointestinal tract in cases where apparent ferentially involve the sigmoid colon affected by diverticu- Crohn's disease complicates diverticular disease of the lar disease.7-'0 Crohn's disease of the sigmoid colon sigmoid colon. l may also induce diverticulitis in patients with diverticular disease.8 Radiological examination of the sigmoid colon by barium enema may help in the diagnosis of dual patho- Luminal inflammation in diverticulosis on September 25, 2021 by guest. Protected copyright. logy. The presence of transmural fissuring and extra- Diverticular disease has previously only been considered an luminal longitudinal sinus tracts are the most helpful inflammatory condition when inflammation of the diver- distinguishing features.7 8 16 Endoscopic examination may ticula, diverticulitis, and the adjacent subserosal tissues, show signs of Crohn's disease especially aphthous ulcers. peridiverticulitis, were present. It is increasingly realised Caution may be needed as aphthous ulcers do occur in that luminal mucosal inflammation may occur in diverticu- diverticulosis associated mucosal inflammation and are lar disease although, given the frequency of diverticulosis, not, in this situation, specific for Crohn's disease. 14 this form of inflammation seems to be comparatively While there are characteristic clinical, endoscopic, and unusual.12-14 Various epithets have been given to the radiological features of Crohn's disease, the diagnosis is condition including diverticular colitis, segmental colitis, usually only fully established by pathological assessment. sigmoiditis, and crescentic colitis. The first of these would The three pathological hallmarks of the disease are seem the most preferable. Rectal bleeding is a characteris- transmural inflammation, epithelioid cell granulomata, tic clinical presentation.'2-14 Endoscopically intramucosal and fissuring or fistula formation. While biopsies may haemorrhage, congestion, and granularity can affect the strongly suggest the diagnosis and are sometimes diagnos- mucosa away from the diverticula'3 and especially the tic, a definitive diagnosis of Crohn's disease is often only crescentic mucosal folds.'2 In some patients the disease made at the time of intestinal resection. It is clear from is more continuous within the sigmoid colon.'314 The several papers describing the association of sigmoid unifying attribute is that the disease is wholly confined to Crohn's disease and diverticulosis that the diagnosis was the segment affected by diverticular disease.'2-14 indeed made at the time of resection.7 9 10 All three patho- Diverticular colitis has been associated with various logical hallmarks of Crohn's disease may be seen as a result pathogenetic mechanisms. Diverticulosis is accompanied by of complicated diverticular disease alone." Tralismural bowel shortening and mucosal redundancy. The pressure inflammation and fissuring/fistulation may be associated effects allied to the excessive mucosa induce mucosal pro- with diverticulitis and peridiverticulitis while granulomata lapse and polypoid change.20 21 Pathological examination of can occur as a reaction to intraluminal material escaping these polypoid lesions shows inflammatory changes but with into the tissues adjacent to diverticula. Even granuloma- the characteristic features of mucosal prolapse.'2 21 22 Such

Leading articles express the views of the author and not those ofthe editor and the editorial board. 802 Shepherd polypoid mucosal prolapse with inflammation may occur prevalence of either disease would suggest while patho- in pre-diverticular disease, when the muscular changes of logical evidence intimates that the association may be the disease are present but diverticula themselves have not exaggerated. The situation is just as uncertain with ulcera- yet developed.20 By no means all cases with inflammation tive colitis, because of mimicry of that disease by luminal in the luminal mucosa can be ascribed to prolapsing inflammation in diverticular disease. In some patients the mucosal folds for in many cases the endoscopic and patho- latter may represent a specific form of inflammatory bowel Gut: first published as 10.1136/gut.38.6.801 on 1 June 1996. Downloaded from logical appearances are unlike those of mucosal prolapse disease, which responds well to treatment that is effective and pathological changes vary from non-specific inflam- in IBD. Occasional cases of diverticular colitis suggest an mation12 23 through to intense active inflammation with intriguing relation between diverticular colitis and ulcera- crypt abscesses, crypt architectural distortion, and tive colitis, which may provide insights into the patho- pronounced chronic inflammation, closely mimicking genesis of ulcerative colitis. active chronic ulcerative colitis. 12-15 22 Suggested mecha- NEIL A SHEPHERD nisms for this active inflammatory condition ofthe sigmoid Gloucester Gastroenterology Group, Gloucestershire Royal Hospital, colonic mucosa have included relative ischaemia of the 3NN sigmoid colon, increased exposure to intraluminal Gloucester GLI antigens and toxins, and changes in bacterial flora related 1 Manousos ON, Truelove SC, Lumsden K. Prevalence of colonic diverticu- to stasis.'2 Many of these cases of diverticular colitis losis in the general population of Oxford area. BMJ 1967; 3: 762-3. respond favourably to treatment similar to that given for 2 Hughes LE. Postmortem survey of diverticular disease of the colon. Gut 1969; 10: 336-51. IBD. 12-15 3 Shapiro PA, Peppercorn MA, Antonioli DA, Joffe N, Goldman H. Crohn's disease in the elderly. Am Jf Gastroenterol 1981; 76: 132-7. 4 Carr N, Schofield PF. Inflammatory bowel disease in the older patient. BrJ Surg 1982; 69: 223-5. Diverticulosis and ulcerative colitis 5 Tchircow G, Lavery IC, Fazio VW. Crohn's disease in the elderly. Dis Colon Rectum 1983; 26: 177-81. While diverticular colitis may closely resemble ulcerative 6 Zimmerman J, Gavish D, Rachmilewitz D. Early and late onset ulcerative colitis pathologically, in most cases a rectal biopsy specimen colitis. Distinct clinical features. J Clin Gastroenterol 1985; 7: 492-8. 7 Schmidt GT, Lennard-Jones JE, Morson BC, Young AC. Crohn's disease is normal and there is no other preceding or succeeding evi- of the colon and its distinction from diverticulitis. Gut 1968; 9: 7-16. dence of IBD outside the sigmoid colon.'2-15 22 However, 8 Meyers MA, Alonso DR, Morson BC, Bartram C. Pathogenesis of diverticulitis complicating granulomatous colitis. Gastroenterology 1978; two recent series have reported five cases presenting with 74: 24-31. diverticular colitis with pathological features, in the sigmoid 9 Berman IR, Corman ML, Coller JA, Veidenheimer MC. Late onset Crohn's disease in patients with colonic diverticular disease. Dis Colon Rectum colonic mucosa, identical to ulcerative colitis but with 1979; 22: 524-9. endoscopically and histologically normal rectal mucosa, 10 McCue J, Coppen MJ, Rasbridge SA, Lock MR. Coexistent Crohn's disease and sigmoid diverticulosis. Postgrad Med J 1989; 65: 636-9. who have subsequently developed classic distal ulcerative 11 Shepherd NA. Pathological mimics of chronic inflammatory bowel disease. colitis with characteristic rectal involvement.'2 14 These Y Clin Pathol 1991; 44: 726-33. 12 Gore S, Shepherd NA, Wilkinson SP. Endoscopic crescentic fold disease of patients have responded well to similar treatment to that of the sigmoid colon: the clinical and histopathological spectrum of a IBD.12 14 distinctive endoscopic appearance. IntJ Colorect Dis 1992; 7: 76-81. 13 Peppercorn MA. Drug-responsive chronic segmental colitis associated with A diagnosis of ulcerative colitis, in the absence of diverticula: a clinical syndrome in the elderly. AmJ Gastroenterol 1992; 87: demonstrable abnormality of the rectum, is, in traditional 609-12. http://gut.bmj.com/ 14 Makapugay LM, Dean PJ. Diverticular disease-associated chronic colitis. view, untenable but relative sparing of the rectum is now AmJ SurgPathol 1996; 20: 94-102. well described.24 25 Could these cases of apparent IBD in 15 Hart J, Baert F, Hanauer S. Sigmoiditis: a clinical syndrome with a spec- trum of pathological features, including a distinctive form of IBD. Mod older patients represent a distinct form of chronic ulcera- Pathol 1995; 8: 62A. tive colitis, which seems to start in the sigmoid colon 16 Marshak RH, Janowitz HD, Present DH. Granulomatous colitis in associa- tion with diverticula. N EnglJf Med 1970; 283: 1080-4. affected by diverticular disease and progress to more 17 Morson BC, Dawson IMP, Day DW, Jass JR, Price AB, Williams GT. classic ulcerative colitis? Given the apparent rarity of such Inflammatory disorders. In: Morson & Dawson's gastrointestinal pathology, 3rd ed. Oxford: Blackwell Scientific, 1990: 521. on September 25, 2021 by guest. Protected copyright. cases, perhaps of more interest is the potential evidence 18 Lee FD, Maguire C, Obeidat W, Russell RI. The significance of cryptolytic these cases provide us with in terms of the pathogenesis of lesions in inflammatory bowel disease. Gut 1995; 37: A21. 19 Graham DM, Appelman HD. Crohn's-like lymphoid reaction and colorec- ulcerative colitis. Pathologists are well aware of the focal tal cancer: a potential histologic prognosticator. Mod Pathol 1990; 3: disease seen in ulcerative colitis in blind-ending parts of 332-5. 20 Mathus-Vliegen EMH, Tytgat GNJ. Polyp-simulating mucosal prolapse in the large intestine such as the appendix26 and the caecum27 (pre-) diverticular disease. Endoscopy 1986; 18: 84-6. with histologically normal proximal colon. Ulcerative 21 Kelly JK. Polypoid prolapsing mucosal folds in diverticular disease. Am J7 Surg Pathol 1991; 15: 871-8. colitis is primarily a disease ofthe rectum where a degree of 22 Cawthorn SJ, Gibbs NM, Marks CG. Segmental colitis: a new complication faecal stasis is inevitable. There is current interest in the of diverticular colitis. Gut 1983; 24: A500. 23 Sladen GE, Filipe MI. Is segmental colitis a complication of diverticular role of faecal bacterial mucolytic enzyme activity, disease? Dis Colon Rectum 1984; 27: 513-4. especially sulphatases and sialidases, and mucolysis in the 24 Burnham WR, Ansell ID, Langman MJ. Normal sigmoidoscopic findings in severe ulcerative colitis: an important and common occurrence. Gut 1980; pathogenesis of ulcerative colitis.28 29 Faecal stasis and 21: A460. activity of these bacterial enzymes could be the link, in 25 Spiliadis CA, Spiliadis CA, Lennard-Jones JE. Ulcerative colitis with rela- tive sparing of the rectum. Clinical features, histology and prognosis. Dis ulcerative colitis, between involvement of the rectum and Colon Rectum 1987; 30: 334-6. disease in these other blind-ending structures, the caecum, 26 Davison AM, Dixon MF. The appendix as a 'skip lesion' in ulcerative colitis. Histopathology 1990; 16: 93-5. appendix, and sigmoid diverticula. Could such a theorem 27 von Herbay A, Starlinger M. Pathologie der idiopathischen chronisch- also explain the apparent protective effect of appendicec- endzundlichen Darmerkrankungen. In: Alder G, ed. Morbus Crohn Colitis ulcerosa. Berlin: Springer-Verlag, 1993: 132-57. tomy against ulcerative colitis?30 28 Corfield AP, Williams AJK, Clamp JR, Wagner SA, Mountford RA. Degradation of bacterial enzymes of colonic mucus from normal subjects and patients with inflammatory bowel disease: the role of sialic acid metabolism and the detection of a novel esterase. Clin Sci 1988; 74: Conclusion 71-8. 29 Tsai HH, Dwarakanath AD, Hart CA, Milton JD, Rhodes JM. Increased Diverticular disease may be associated with complex faecal mucin sulphatase activity in ulcerative colitis: a potential target for inflammatory characteristics that may closely mimic IBD. treatment. Gut 1995; 36: 570-6. 30 Rutgeerts P, d'Haerns G, Hiele M, Geboes K, Vantrappen G. Clinical evidence would suggest that the coexistence of Appendectomy protects against ulcerative colitis. Gastroenterology 1994; diverticulosis and Crohn's disease is commoner than the 106: 1251-3.